The nation's recent cluster of mass shootings have reminded people that they can become victims even in the most benign public places and revived the sort of insecurity that swept the country after the Sept. 11, 2001, terrorist attacks, more than two dozen interviews show.

Antonio Tarver has fought 29 times, but his 10-year pro boxing career can be defined by two bouts. In May 2004, Tarver's second-round TKO against Roy Jones Jr. rocketed him to the top of the light heavyweight division, and, just as swiftly, his 12-round loss to Bernard Hopkins in June 2006 brought him crashing down.